Inertia absorber



Sept. 24, 1946. H. A. HERZIG 2,408,057,

INERTIA ABSORBER 'Filed Nov. 30, 1943 Patented Sept. 24, 1946l Henry A.- Herzig, Port Washington, N. Y., assignor to Sperry Gyroscope Company,l Inc., a corporation of New York v Application November 30, 1943,'Serial No. 512,319

6 Claims.

This invention concerns an inertia absorbing device for use with a reversing mechanism to absorb the inertia of a load vduring operation of for stopping movement of an output member to` absorb the inertia of Va loadv during the reversing operation. Y g

A further` object of the invention is to provide a computing mechanism with an inertia, absorber actuated synchronously with an intermittently operable reversing mechanism to absorb the inertia of the load driven by the computing mechanism during the reversing operation.

Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawing, A f

' i restA movement of the output shaft thereby absorbing the inertia of the load without interferwherein Fig. 1 is a perspective View of a sine computing mechanism embodying the invention in a preferred form, somevparts being broken away for purposes of clearness;

in Fig. 1 showing the stop members positioned -for stopping rotation ofthe output shaft in one direction; and y Y Fig. 3 is a similar side elevation of the stop 3.0 Fig. 2 is a side elevation of the stop mechanism the sine of the inputvangle. .3 5

mechanism, but showing the stop members'posi- Etioned for stopping rotation ofthe output shaft in the opposite direction. i Y y The present invention is particularly useful in Aconnection with trigonometric computing devices such as those for computing a, particular trigonometric function of .an angle. One device for determining the trigonometric function of an angle is a cam Which may be rotated, or votherwisemoved, according to a particular angle, By properly laying out the surface of the cam, it maymove a follower 'according to any predetermined function of the angle according to which the cam is rotated. c

For example, from trigonometryit is known that the sine value of an angle increases from zero to unity for anglesv of from Ojto 90 degrees, and decreases from unity to zero for angles between 90 and 180 degrees.V It is sometimes possible .to provide a cam surface which will compute the sine langles kover a complete 360 range. In other cases, it is `,necessary to move the cam in one direction from.0. to 90, then reverse the cam and move `it inthe opposite directionfromf to 180. i

The present invention is particularly `useful inconnection-with the latter type. of mechanism. Since the speed of movement of the cam remains constant, providing the rate of change of the input angle is constant, but only the direction of the output is changed, any mechanical load driven by the output of the cam mustbereversed from a given speed invone direction to the same speed in an opposite direction. Obviouslythis places a very heavy load on the computing device.

According to the present invention, the inertia absorber operates synchronously with the reversal of direction toabsorb the inertia of the load independently of the computing device. As appliedto a trigonometric computing device, the

reversing mechanism operates intermittently for ing with the normal operation of the computing device.

The invention is illustrated inthe drawing as applied toay sine computing unit utilizing a pin cam which is rotated according to any given angle, and drives an output shaft according to Thev direction of rotation of the pin cam must be changed for each ninety degrees of the input angle. Obviously, the output member and its load is reversedat the same time. Without the provision of the inertia absorber, the pins`on the cam would have to absorb the inertia forces of the load which are quite large when it is realized that under certain conditions, the entire apparatus changes from a given speed in one direction to a corresponding speed in the opposite direction.

As shown in Fig. 1, an input shaft Il is driven I4, are adapted to mesh with corresponding clutch members IS and 20 on gears 2| and 22, respectively, which are also rotatable on the vshaft I5.

' The gear 2|, when the clutch members I1 and I9 are engaged, drives through gear 23 on shaft 24 which rotates gear 25 to drive a broad-faced gear 25. The gear 25 is keyed to shaft 21 to drive bevel gear 25 which operates through bevel gear 29, shaft 3| and pinion 32 that meshes with a gear 33 on the periphery of a pin cam 34.

When the clutch members I8 and 20 are engaged, as by shifting of the sleeve I4, the gear 22 drives directly through the gear 25 and shaft 21 to rotate pinion 32 in the opposite direction to its previous direction of rotation, whereby the `direction of` rotation of pin cam 34A is reversed. As shown in the drawing, pins 5,5 on the face of the pin cam 34 are arranged in spiral fashion to provide the desired sine function.

The reversing mechanism is actuated, as will be explained, according to the position of the input shaft II, whereupon the, `sleeve I4 is shifted longitudinally of the shaft I5 to cause the shaft EI to drive the pin cam `(t4 in one direction. or another, depending upon the angular input represented by the shaft II. As previously pointed out, the ydirection of rotation of pin cam 34 must be reversed for each ninety degree change in the input angle; that is, the Pin cam 34 is driven in one direction for an input angle of from to 90, but reversed for angles from 90 to 180. This .procedure continues for each-ninety degree change in the input angle.

In order to operate the reversing mechanism at each ninety degree angle, the input shaftk II has a bevel gear 4I meshing with a bevel gear 42 that is freely rotatable on shaft 43 and drives a gear 44 which, in turn, ro'tatesa gear 45 that is rotatable on a shaft Iii` arranged parallel to the shaft 43. The gear 45 operates through a Geneva accumulator mechanism, designated generally at 50, which intermittently turns the shaft 45. The shaft 45 thus turns reversing member I which engages collars 52 and 53 on the sleeve I4 to shift the sleeve together with the driving gear I3 longitudinally of the shaft I5. lThe gear 45 is keyed to a segment gear 41 and a locking disc 48 which cooperate in a conventional manner with teeth 49, 49 to intermittently turn Geneva gear 55.

The Geneva gear 55 is fixed to another segment 55 and locking Adisc 51 to intermittently operate Geneva gear 58, whiche in turn, operates another Geneva mechanism vincluding segment gear 59, locking disc 6| and gear 62. The gear 52 also actuates a Geneva mechanism including segment gear 53, locking disc 54 and gear 65, which is fixed on shaft 45. By appropriately arranging the gear ratios of the driving gear and the Geneva accumulator mechanism, it is possible to turn the shaft 46 through an angle of 180 to actuate the reversing member 5I thereby reversing the direction of the drive for the pin cam 34. As shown in the drawing, the reversing member 5I is turned through 180 in two steps of one-fourth of a revolution each lfor each ninety degree change in the input angle. The reversing member 5| thereby actuates the reversing mechanism to reverse the ydrive of the pin Cam for each ninety degrees of the input angle represented by the position of shaft II.

The pins 35 on the pin cam 34 drive a follower gear 61 that is mounted on a square shaft (it and is slidable longitudinally thereof. In order to support the follower gear 61, a guide rod 59 may be arranged to engage a guide member 1I slidable on the square shaft 68 to guide movement of the follower gear 61 as it slides along the shaft 58 to follow the spirally arranged pins 36.

The shaft 68 `drives through gears 12 and 13 to rotate an output shaft 14 which may be utilized to drive` any desired load represented diagrammatically at 15.v A stop member 11, in the form of a segmental projection, is mounted on the shaft 14 and is adapted to engage aninterittently actuated stop 19 which is mounted on a shaft BI for intermittent movement synchronously with the operation of the reversing mechanism to stop rotation of the output shaft 14 as well as movement of the load 15.

The mechanism for intermittently actuating the stop 19 consists of a Geneva accumulator mechanism 83 that is similar to the accumulator 50 previously described. It consists of al series of Geneva mechanisms carried on parallel shafts 84 and 35. The input of the Geneva accumulator 83 isvdriven from shaft 14 asV by gears 86 and 81, which rotate segmental gear 88 and locking disc 89, which cooperate with Geneva gear 9| on shaft 85, to intermittently'rotate segmental gear 92 and locking disc 53 of a `second Geneva mechanism. The segmental gear 92 rotates Geneva gear S3 on the shaft 84, that drives segmental gear S4 and locking disc 95 which operate a Geneva gear 86 on the shaft 85. This Geneva gear 96 drives-still another segmental gear 91 and locking disc 93 which operate a Geneva gear 99 on the shaft 54. rhis lat-ter Geneva gear intermittently rotates segmental gear IUI and locking disc |02, which cooperate with Geneva gear |03 to intermittently turn spur gear |05 on the shaft 85.

From this `description it will be apparent that the Geneva accumulator 33 is driven by the output shaft 14 and operates to intermittently turn the gear |05 through approximately one quarter of a, revolution for a given number of revolutions of the output shaft 14. The gear |05 drives through idle gears |01 and |08 to turn a gear |09 which is xed to the stop 19 on the shaft 5I. In this manner, the stop 19 is also intermittently turned through approximately one fourth of a revolution for a given number of revolutions of the output shaft 14.

When the output shaft 14 is rotated in a counterclockwise direction, as shown by the arrow in Figs. 1 and 2, the stop 19 is intermittently turned in a clockwise direction until the output shaft 14 reaches a position at which thev reversing mechanism is actuated to reverse the direction of movement of the pin cam k34. At this instant, the stop 19 is operated by the Geneva mechanism 83 to move from position A, as shown in dotted line in Fig. 2, 'to position B, where it engages the segmental stop engaging member 11'.

As the stop engaging member 11 contacts the stop 19, the inertia of the load 15 is absorbed. by the two stop members 11 and 19, and is not transmitted to the pins 35 on the pin cam 34 when it reverses its direction of rotation.

When the reversing mechanism reverses the direction of rotation of the pin cam 34, it also reverses the direction of the output shaft 14 and the loadv 15', thereby immediately operating through the Geneva accumulator mechanism t0 a clockwise ydirection to 'a position at which the reversing mechanismr again changes the direction of rotation of the pin cam 34, whichr corresponds to the center position of the follower gear 59 on the pins 36, the Geneva accumulator 83 rotates the stop 19 from position C, to position D, as shown in Fig. 3, where it engages the stop engaging member 'Il to absorb the inertia of the load during the operation of the reversing mechanism. As soon as the direction of rotation of the pin cam 3d is again reversed it begins rotating output shaft M in a counter-clockwise direction so the stop member 'i9 is moved by means of the Geneva accumulator mechanism 83 from position D to position C, from which point it is intermittently turned until `it reaches stop position B, as shown in Fig. 2, when the reversing mechanism is again operating. i

From the foregoing description it will be apparent that the input shaft Il may continuously rotate in either direction As it reaches a point in its rotation corresponding to an input angle of 90, reversing member 5l is actuated by theA Geneva accumulator 5t operating the reversing mechanism to reverse the direction of rotation of the pin cam 3d together with output shaft 14, relative to the direction of rotation of input shaft I I. At the instant of operation of the reversing mechanism, stop i9 moves into position t0 contact stop engaging member 'H to'absorb the inertia of the load 'i5 by stopping the movement of output shaft M. This relieves the force of the jloads inertia from the pins 38 on the pin cam 34,

- While the invention is described in connection with a pin cam trigonometric computing mechanism for computing a sine of a given input angle, it should be understood that it may be applied to other types of mechanisms, in which it is desired to intermittently reverse the direction of movement of an inertia load. The operation of the inertia absorber stops synchronously with the operation of the reversing mechanism relieves the'strain due to the inertia of thel load from the driving mechanism and avoids damage thereof.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, itis intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a computing mechanism of the character described, the combination of an input member, a pin cam driven by said input member, a reversing mechanism connectedY between said input member and said pin cam for changing the direction of movement of said pin cam relative to said input member, an accumulator device driven by said input member for intermittently actuating said reversing mechanism to change the direction of movement of said cam, an output member driven by said pin cam, stopping means for arresting movement of said output member, and

6 an accumulator device driven by said output Ymember for operating said stopping means synchronouslywith the operation of saidreversing mechanism to arrest movement of said output member during thek reversing operation.

2. In an apparatus of the character described, the combination of an input member, a pin cam driven thereby, a reversing mechanism connected between the input' member and pin cam for changing the direction of movement of the pin cam relative to that of the input member, an output shaft driven from the pin cam, means for absorbing the inertia of the outputshaft on the operation of the reversing' mechanism comprising a first stop member positioned by the output shaft, an accumulator driven by the output shaft, a second stop rmember intermittently driven by the output of the accumulator into the the combination of an input member, a pin cam driven thereby, a reversing mechanism connected 'between the input member and pin cam for changing the direction of movement thereof relative to the direction of the input member, an output shaft driven from the pin cam, a first stop member fixed to the output shaft, a Geneva accumulator driven by the output shaft, and a second stop member driven by the accumulator disposed to be actuated thereby intermittently into the path of the first stop member, the accumulator being synchronized with the reversing mechanism and effective on actuation thereof to position the second stop member so as to be engaged by the rst stop member, thereby arresting the movement of the output shaft.

4. In an apparatus of the'character described, the combination of an input member, a pin cam driven thereby, a reversing mechanism connected between the' input member and pin cam for changing the direction of movement of the pin cam relative to that of the input member, an output shaft driven from the pin cam, means for absorbing the inertia of the output shaft on the operation of the reversing mechanism comprising a first stop member fixed to the output shaft, an accumulator comprising a Geneva mechanism driven bythe output shaft, a second stop member intermittently driven by the output of the accumulator into the path of the first stop member, the accumulator being synchronized with the reversing mechanism and effective on the operation thereof to position the second stop member so as to be engaged by the first stop member, thereby arresting the' movement of the first stop member and the output shaft.

5. In an apparatus of the character described, the combination of an input member, a pin cam driven thereby, a reversing mechanism connected between the input member and pin cam for changing the direction thereof with respect to the input member, an output shaft driven from the pin cam, means for absorbing the inertia of the output shaft on reversal of the direction of the pin cam comprising a first stop member fixed to the output shaft, an accumulatorY comprising a Geneva mechanism driven by the output shaft, a second stop member driven in a direction opposite to that .ofV the first intermittently into the 7 path 0f the rst stop member by the output of the accumulator, the accumulator being effective at they time of the reversing operation of the reversing mechanism to position the second stop member to arrest the rst and thereby arrest the output shaft.

6. In a computingv mechanism for computing functions of angles, the combination of an input member displaced in accordance with the angle of which the function is to be computed, a pin cam laid out according to the function to be computed displaced by the input member, a reversing mechanism connected between the input member and the pin cam for changing the direction of the pin cam relativeV to the-input member, an accumulator device driven by ther input member for intermittently actuating the reversing mechanism to change the direction of movement of the cam, an output member driven by the pin cam, stopping means for arresting the movement of the output member, and an accumulator device driven by said output member for operating the stopping means synchronously with the operation of the reversing mechanism to arrest movement of the output member during the reversing operation. i

HENRY A. HERZIG. 

